Mining machine and method



1969 P. FRENYO ETAL MINING MACHINE AND METHOD 4 Sheets-Sheet 1 FiledAug. 28, 1967 ll ullnllllllll'll mvnvrons. PAL EREN ya a HE/NZ x1.OTTSCHEN Nov. 11, 1969 P. FRENYO ETAL MINING MACHINE AND METHOD 4Sheets-Sheet 2 IN VE/V TORS PAL ERENYO 8 HE/NZ KLOTTSCHEN y 7 704mg! MAttorneys Filed Aug. 28, 1967 NOV. 11, 1969 FRENYO L 3,477,762

MINING MACHINE AND METHOD Filed Aug. 28, 1967 4 Sheets-Sheet L Pita-.4-

INVENTORS. ,PAL REA/r0 a B HE/NZ Kw'rrscHE/v f far-nay;

United States Patent US. Cl. 299- 4 Claims ABSTRACT OF THE DISCLOSUREThis patent discloses a mining machine, and method of using it, forheading into hard rock or mineral. Satisfactory cutting of hard rock,with a minimum of pressure on the tool, is obtained by providing amining machine of the kind with a frame, a tool carrier pivoted on thelongitudinal axis of the passage to be cut, and a plurality of rings ofcutter or roller bits mounted on the tool carrier, each at a differentradial distance from the longitudinal axis of the passage and eachpivoted about an axis inclined toward the axis. According to theinvention, each ring has its bits spaced at a common distance, so as tocut a number of steps of equal height into the rock or mineral. Thispatent further discloses a method of operating such a machine, accordingto which the bit rings are rotated more rapidly than the tool carrier,and the tool carrier is advanced toward the face being cut at a rate'sufliciently low that in a single complete rotation the cutter orroller bits on a bit ring cut away only a part of the step of coal withwhich they come into contact.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to mining machines and methods of using same.

Description of the prior art It is known to provide a mining machineequipped with a cutter drum in the shape of a truncated cone at thefront end of the machine, where the small front face and shell of thetruncated cone are fitted with cutter bits. In a machine of this type,the cutter drum is carried by an arm pivoted on the machine frame, sothat it can be swiveled in all directions; the arm is at right angles tothe end face so that it will guide the cutter drum over the roadwaycross section which is to be cut away.

Also known are mining machines that consist of a frame which can bemoved to the longitudinal direction of the gallery or roadway, the framebeing equipped with a tool carrier facing the mineral to be cut, thistool carrier being pivoted on the longitudinal center line of thegallery to be made. In known machines of this kind, two or more rings ofbits, which may be cutter bits or roller bits, are arranged outside thelongitudinal center line of the gallery to be made and are pivoted atdifferent radial distances from the longitudinal center line of the toolcarrier, so that the bit center lines are inclined toward the gallerycenter line. These bit rings detach the mineral by means of roller orcutter bits arranged at the front of the cutting tool, by cuttingradially into the hard rock or mineral. Known machines of this kind havenot, however, been so constructed as to exhibit certain featuresinvented by the applicants and hereinbelow described, and as a result,though such machines prove adequate for mining minerals of low or mediumhardness, they exhibit the disadvantages of requiring substantialforward pressure and having as a result rather short tool life when3,477,762 Patented Nov. 11, 1969 they are used for the mining ofrelatively harder rock or minerals.

SUMMARY OF THE INVENTION In accordance with the present invention, theabovementioned disadvantages are overcome by providing a mining machinethat is substantially similar to that described above, except that thereare provided on the exteriors or shells of the cone-shaped cutter drumsa number of cutter or roller bits, so spaced and arranged as to leave inthe face of the coal being cut a number of steps of equal height. Thismakes it relatively easier to fdislodge the hard rock or mineral withwhich the roller or cutter bits are coming into contact, as the bits arecoming into contact with pieces of hard rock or mineral that are notpart of a flat face, as would be the case, for example, with cutter orroller bits arranged only on the end, rather than the exterior, of acutter drum of generally frustoconical shape. The favorable effect ismaximized and enhanced by using a number of steps of equal height. Thepresent invention further concerns a method of operating a miningmachine having the feature indicated above, in accordance with which thecutter drums are advanced into the hard rock or mineral at a relativelylow rate of speed, e.g., so that of the height of the step with which anindividual cutter or roller bit comes into contact in a particular passof the cutter or roller bit into the hard rock or mineral comprisingthat step, only a relatively small part, for example, the outermostone-third of the step, lies within the volume swept through by thecutter or roller bit. This is conveniently done by providing hydraulicmeans for advancing the tool carrier carrier away from the frame andinto the hard rock or mineral to be cut, and providing means driven bysaid hydraulic means for rotating the tool carrier, so that the toolcarrier rotates at a relatively low rate of speed. The cutter drums, onthe other hand, are rotated by electrical motors separately provided,and they travel at a much higher rotational speed, as is required inorder that their cutter or roller bits strike the hard rock or mineralwith sufficient energy to dislodge it. To allow for accelerating ordecelerating the mining operation, in accordance with the hardness ofthe mineral currently being encountered, it is preferred to provide aninfinitely variable power linkage or transmission, for example, one ofhydraulic nature, between the means for driving the tool carrier forwardolf the frame and into the face and the means for causing the toolcarrier to rotate about its axis.

It is essential, to a proper understanding of this invention, todistinguish between what the tool carrier is doing and what the cutterdrums are doing. Over a period of time, such as one minute, the toolcarrier will have made one revolution, carrying it about one-third ofthe height of the step deeper into the face of hard rock or mineral soas to leave, as a result of the many rotations that the cutter drum willhave made in that time, a stepped groove, one for each frustoconicalcutter drum used. In a particular individual revolution of a cutterdrum, only a relatively small amount of hard rock or mineral isencountered and dislodged, namely, that with which the roller or cutterbits on the cutter drum will now be brought into contact with, as aresult of the relatively slight rotation of the tool carrier that hastaken place during a single revolution of the cutter drum. This meansthat a bit on the exterior of the cutter drum rotates freely withoutencountering any hard rock or mineral under it reaches a point, in itscircumference of travel at which it begins to encounter a small volumeof coal, namely, a volume about one-third the height of an individualstep (more or less, depending upon the rate of advance of the toolcarrier forward into the hard rock or mineral, compared with the heightof individual step,

as determined by the spacing of the roller bits on the frust'oconicaldrum upon which they are mounted) and extending for a distance about theperiphery of the step cut by the machine in one rotation of the toolcarrier (this distance being more or less, depending upon the rotationalspeed of the tool carrier and the rotational speed at which theelectrical motors drive the frustoconical cutter drum, highercutter-drum rotational speeds or lower tool-holder rotational speedsmaking the volume to be cut smaller). It will be appreciated that byusing a tool holder having mounted thereon a number of cutter drumsspaced at different radial distances from the longitudinal center lineof the passage to be cut, it will be possible to cut into hard rock ormineral a passage of large diameter, leaving neither ribs nor a core,and at the same time, as a result of the considerations explained above,the forward pressure on the tool carrier to drive the machine will beminimized and the tool life will be improved.

BRIEF DESCRIPTION OF THE DRAWINGS A complete understanding of theinvention may be obtained from the foregoing and following description,taken together with the accompanying drawings, in which:

FIGURE 1 is a side view of a mining machine in accordance with thepresent invention;

FIG. 2 is a front view of the mining machine of FIG. 1;

FIG. 3 is a diagrammatic plan view of the mining machine of FIG. 1;

FIG. 4 is an illustration to a different scale, illustrating theoperation of the machine of FIGS. 1-3;

FIG. 5 is an illustration of the end face cut by the use of the machineof FIGS. 1-3; and

FIG. 6 is a perspective part view of the end face of FIG. 5, taken onthe line VIVI of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there isshown a tube-shaped frame 1 and a machine casing 2 longitudinallydisplaceable inside the frame 1, as well as hydraulic cylinders 3arranged in pairs on different sides of the machine, which are connectedto the frame 1 and rest with their shoes 4 shaped to suit the roadwaycurvature on the roadway floor and roof and thereby clamp the frame 1 inposition, holding it centrally located with respect to the roadwaycenter line, with the aid of guide links 5. Hydraulic cylinders 6 serveto displace the machine casing 2 toward an end face 7. The cylinders 6are put under pressure by hydraulic pump 8, which is driven by ahydraulic motor 9, best seen in FIG. 3. Since this hydraulic motor 9drives also the main shaft 11, which is located in the longitudinalcenter line 26 of the roadway 10, the rotary motion of the main shaft 11and the feed motion of the two hydraulic cylinders 6 are at a definiteratio, but this ratio may be infinitely varied by adjusting the pump 8,and the feed motion can thus be brought up to the required order ofmagnitude. The energy required to drive the hydraulic motor 9 issupplied through hoses 14 by a hydraulic pump 13, which is driven by anelectrical motor 12 and arranged at some distance behind the miningmachine in the roadway on an oil tank 32, the tank 32 and motor 9 beingcapable of traveling together in the longitudinal direction of theroadway 10.

On the front free end of the main shaft 11, there is arranged, as shownin FIGS. 1 and 4, a tool carrier 15 carrying two bit rings 16 and 17.The bit rings 16 and 17 are arranged on the tool carrier 15 at differentradial distances from the main shaft 11, and they rotate about axes 18and 19 which are inclined with respect to the main shaft 11. Thedifference in the direction of the axes 18 and 19 with respect to themain shaft 11 corresponds to the clearance angle of the roller bits 20arranged on the bit rings 16 and 17; to show this angular relationgraphically would have required complicated drawings, and for the sakeof simplification, a parallel relation is shown in the accompanyingdrawings. The bit rings 16 and 17 are each made in the shape of afrustrum of a cone, and they carry roller bits 20, both on their smallfront face within the roadway end face 7 and on their shell surfaces,the roller bits 20 on the shell surfaces of the bit rings 16 and 17having common spacings of lines of cut, so as to produce, as shown inFIG. 6, a stepped groove, with each of the steps having a distance,proceeding in a direction perpendicularly into the end face 7, of a. Inorder to reduce the shock upon running into the rock and to improve thequiet running of the mining machine, the roller bits 20 can be arrangedhelically on the shell surface of the bit rings 16 and 17. The bit ring16 is driven by an electrical motor 21 and the bit ring 17 is driven byan electrical motor 22. The bit rings 16 and 17 rotate together with thetool carrier 15 and the main shaft 11 slowly about the longitudinalcenter line of the roadway 10.

On account of the arrangement of the bit rings 16 and 17 in the form ofa truncated cone, with an inclination of 45, the roller bits 20 that arearranged with a common distance a of their lines of cut on the shellsurface will make a cut in the roadway end face which corresponds to theprofile of the bit ring, the sides of the cut or groove being stepped.This cut is widened annularly by the rotation of the tool carrier 15,and the cut is taken over the entire roadway cross section, so thatneither core nor ribs are left. By the uniform advance of the machineframe 2 in the longitudinal direction of the roadway, which is effectedby means of the two hydraulic cylinders 6, the epicycloidal orhypocycloidal path of motion of the roller bits 20 is pushed helicallydeeper into the roadway end face 7.

FIGS. 5 and 6 show that the roller bits 20 perform during the rotationabout axes 18 and 19 of the bit rings 16 and 17, cuts whose lengthscorrespond to arcs 22' and 23 or 24 and 25. They come into contact withthe rock only over this comparatively short distance and then detach across section of mineral from its surroundings, the amount detachedbeing governed by the speed of the advance of the mining machine alongthe roadway center line and the speed of rotation of the tool carrier15, as is clearly shown in FIG. 6. The individual roller bits 20penetrate quickly and consecutively into the mineral, which projects insteps and is therefore less securely held, and thus the bits 20 haveadequate time for cooling down, so that they have a long service life.The lead of the helical path along which the bit rings 16 and 17 moveduring their rotary motion about the roadway center line 26 is governedby the selected speed of advance, which, in turn, is controlled by thevolume of liquid supplied by the hydraulic pump 8. In the example of anembodiment shown in FIG. 6, the advance of the machine in the directionof the roadway center line, i.e., in the direction of the arrow 27, perrevolution of tool carrier 15 is equal to b. The mining machine does notoperate here with a maximum speed of advance corresponding to thedistance a of the lines of cut, that is to say, to the depth of thesteps, but rather it detaches by means of the roller bit 20 only theamount of rock or mineral governed by the depth b of the chip and therotary motion of the tool carrier 15 along the length of the are 22, asseen in FIG. 5.

The bit ring 16, which detaches the central part of the roadway end face7 and cuts it free, extending up to the center line 26 of the roadway10, runs around a core 28 that is formed at the center line 26 andthereby crushes it, so that no core-is left in the portion of thepassageway 10 upon which the machine has operated. As also seen in FIG.4, there is an annular ri-b 29 of rock, which projects between the twobit rings 16 and 17 but is, nevertheless, equally worked upon anddislodged by the action of both bit rings 16 and 17. If the bit rings 16and 17 are so arranged that they are adjustable with respect to eachother in the direction of the center line 26, and if the bit ring 16 ismade to advance with respect to the outer bit ring 17, the planes ofmotion of the two bit rings 16 and 17 can be adjusted with respect toeach other in such a way that the rib 29 of rock is detached entirely bythe inner bit ring 16 if the roadway cross section to be cut is suchthat it can be cut with overlapping bit rings. In this way, the volumeof rock to be dislodged is uniformly distributed over both bit rings, sothat they are uniformly loaded.

If the direction of rotation of the outer bit ring 17 is made tocoincide with the direction of rotation of the tool carrier 15, themining machine runs particularly quietly, without shocks, because of thecomparatively small angle at which the roller bits 20 run into the rockor mineral. That is to say, these advantages are obtained when the outerbit ring 17 rotates in the same sense as the tool carrier 15.

As shown in FIG. 2, the outer bit ring 17 is pivoted on the center line30 of the tool carrier 15 and is made radially adjustable in its givenworking position by means of a double-acting hydraulic jack ,31.If thejack 31 is acted upon by hydraulic fluid at a rhythm or in a cycle thatis governed by the rotary motiontof the tool carrier 15, it is possibleto make roadway cross sections that, rather than being round, are of oneor another desired different shape. 7

While we have shown and described herein certain embodiments of ourinvention, we intend to cover as well any change or modification thereinwhich may be made without departing from the spirit and scope of theinvention.

We claim as our invention:

1. In a machine for mining hard rock or mineral comprising a frame, atool carried mounted on said frame for pivotal movement about the centerline of a passage to be cut by said machine and for movement into a faceof said rock or mineral to cut said passage, and a bit ring mounted onsaid tool carrier for rotation about an axis not coincident with saidpassage center line, said bit ring having thereon a plurality of bits,the improvement which consists in having said bit ring shaped as atruncated cone and having said bits so spaced and arranged on theexterior of said cone as to cut into said hard rock or mineral aplurality of steps of equal height, by the exertion of forces directedradially outwardly from said axis and operating upon the hard rock ormineral of one of said steps at a point intermediate of its extent in adirection parallel to said center line.

2. An improvement as defined in claim 1, characterized in that saidmining machine further comprises means operable while the mining machineis in operation for adjusting the distance between the center line of anexterior one of said bit rings and the center line of the passage to becut, whereby roadway passages of different shape may be cut.

3. An improvement as defined in claim 1, further characterized in thatsaid machine comprises infinitely variable transmission means forturning said tool carrier about its axis at different rates of speedwith respect to the speed of advance of said tool carrier away from saidframe.

4. A method of cutting underground passages in hard rock or mineralcomprising dislodging said mineral from a face thereof by cuttingtherein a stepped groove having steps of equal height, said cuttingbeing done by successively bringing into contact with various portionsof the periphery of said stepped groove a rotating member substantiallysmaller than the outside diameter of said annular stepped groove, saidmethod being characterized by the step of moving said rotating memberperpendicularly into said face of hard rock or mineral at a rate ofspeed such that a significant portion but less than the entire extent ofan individual step of said stepped groove is cut during one rotation ofsaid rotating member by means of forces directed radially with respectto the axis of rotation of said rotating member.

References Cited UNITED STATES PATENTS 2,466,709 4/1949 Karr 29986 X3,004,753 10/1961 Silt 299- 3,215,214 11/1965 Caro 29986 X 3,285,35511/1966 Neilson et a1. 334 3,288,532 11/1966 Carver 29986 X 3,387,8936/1968 Hoever 299- 86 X ERNEST R. PURSER, Primary Examiner US. Cl. X.R.

